1. Field of the Invention
The present invention relates to an apparatus and method for automatically adjusting toner density in a color printer, more particularly, by which color density to be fixed can be adjusted according to remaining toner quantity in the color printer.
2. Description of the Related Art
In general, a color printer has four color toners, i.e., yellow, magenta, cyan and black toners contained in cartridges, respectively. The color printer fixes a color toner from its cartridge onto a printing sheet to reproduce a color matching an original as best as possible. Such a color printer is also called a color laser printer.
As shown in FIG. 1, such a conventional color printer includes emulators 10 and 12 for rendering original data, i.e., original text and image data from a PC drive (not shown) and generating a resultant display list, a printer firmware 14 for generally managing the printer and executing a printing command according to the display list and an engine firmware 16 for controllably operating a printer engine in response to the printing command from the printer firmware 14 so that four color toners, i.e., yellow, magenta, cyan and black toners are fixed onto a sheet to reproduce the original data thereon.
After the display list is emulated, the emulators 10 and 12 check-in the printing with the printer firmware 14, which in turn controls the engine firmware 16 to print the checked-in original data so as to output the printed sheet.
The printer firmware 14 measures the remaining quantities of the four toners (i.e., yellow, magenta, cyan and black toners) to determine whether any of the four color toners does not exceed a predetermined level, and if any of the four color toners does not exceed the predetermined level, generates an alarm based upon at least one of visual and audio signals to notify a user of replacement time so that the user can replace the corresponding toner at a suitable time.
In the conventional color printer, however, the engine firmware 16 performs a normal printing according to the information of the display list regardless of the remaining quantities of the yellow, magenta, cyan and black toners contained in their cartridges.
If the remaining quantity of any of the yellow, magenta, cyan and black toners does not exceed the predetermined level, the corresponding color toner fed under a suitable quantity or a reference value mixes with other normal toners when they are fixed onto a paper sheet. This provides the sheet with an image having colors different from those of the original data.